Hey fellow members as most of you know or realize I have a 99 mustang with a 302 ( 308) that is carb , well ive battled every issue possible with this car and I lay money I have had more problems then anyone on such a motor . Im running a msd mechanical advance distributor and I have been told that vacumn advance distributor would be the best for street , but I have tried tuning the mechanical to make due with it , today i realized i had way to much timing I was running 18-20 degrees intial and 18 degrees advance so I had way to much initial . I switched the spring in the distributor to a light blue and a light silver and the bushing is now a silver . inital timing is set at 8 degrees , firing order is the 154 method its a 1974 block with a custom grind cam and I have recently been told that maybe I need to run the H.O firing order instead ?? the exhaust backfire seems to only come from the driver side but whats weird is I adjusted this springs and bushing and set timing correct and the carb was adjusted wack because of the timing being messed up before . Im running a Road Demon 625cfm vacum advance carb its 4 corner idle and all screws are out half a turn right now and the car was running at 8-1000 rpm and was counting the licks off ! sounded better than it ever has ! then i left came back and started if up the engine was cold and the popping and backfire started again!! how could it run perfect and then start that with nothing being changed ? my camshaft is a custom grind 280 duration with a 480 lift . also i looked at my plugs and they have very heavy black carbon on them proble because of the very rich condition the motor was running before ! ANY IDEAS PEOPLE IM READY TO PULL MY HAIR OUT LOL!